Pump or motor



4 Shets-Sheet 2 W. ERNST PUMP OR MOTORV May 19, 1936.

4 Sheets- Sheet 4 Filed May 25, 934

I. I mNm R m NR ,2 M

y w m m 4 Arra/Mir Patents& May 19, 1936 e UNiTED 'STATES PATENT OFFICE PUMP OR MOTOR Walter Ernst, Mount Gilead, Ohio, assignor, by

mesne vassignments to The Hydraulic Press Corporation, Inc., Wilmington, Del., a coi-peration of Delaware Application May 23, 1934', Serial No. ?27,081

3 Clams. (ei. 103-161) pisten crossheads having surface grooves and conduits leading to these grooves for the purpose of supplying lubricant to the thrust surfaces.

Another object is to provide such a pump or motor wherein the pisten is provided With a por tion arranged to be guided on opposite sides during its reoprocation by correspondingly formed portions on the primary rotor'.

Another object is to provide such a pump or motor wherein the thrust surface of the crosshead is grooved to receive an extended portion of the piston, this extended portion being adaptedto engage guide portions on the primary. rotor arranged on opposite sides thereof, the crosshead proper being likewise adapted to engage the secondary rotor.

Another object `is to provide such a pump or motor wherein the rotating parts are supported on preloaded ball bearings which serve to place a preliminary load thereon in order to take out most of the elastic deformation thereof.

Another object is to provide means where'by the outer end of the pintle and primary rotor will be supported by means associated with the drive shaft, the latter being rotatably supported in the casng so that a. compact and yet eflicient construction results.

In the drawings:

Figure 1 is a central vertical section through the pu'mp or motor of my invention, taken 'in a transverse plane, passing through the axes of the cylinder bores Figure 2 is a central longitudinal vertical section therethrough;

Figure 3 is a. front elevation of the primary 'rotor used in the pump or motor of my invention;

Figure 4 isa sideelevation, partly in section, of the primary rotor shown in F'igure 3;

Figure' is a side elevation, partly in section, of the pisten and crosshead, of this invention; Figura 6 is an end elevation of the piston and crosshead shown in Figura 5;

Figure'7 is a top plan view of the pisten and crosshea-d shownin Figur 5; i

Figure 8 is a side elevation of the crosshead guide block used in this pump or motor;

Figure 9 is a central longitudinal horizontal section through a modified form of pump or motor employing pre-loaded ball bearings.

Referring to the drawings in detail, Figure 2 shows a hydraulic pump' or motor having a casing composed of end plates i and 2 intereonnected by an' annular casing ring 3, as by the bolts ti. The

end plate i is provided with a boss or projecting lo portion 5, having a bore ti in which is mounted a pintle l. The outer end of the pintle 'l is threaded as at 8, these threads being engaged by the nut 9. The tightening of the nut 9 causes the pintle 'i to be firmly held against the projecting boss 5 w by the pintle shoulders lil at one end and the nut 9 at the other end. The pintle 'i is provided with the usual internal bores 22, 23, Zt, and 25 for the passage of fluid, these communicating with the external piping by means of transverse passageways, such as fli, in the projecting boss 5.

The inner end of the pintle 'i is providedwith a reduced diameter portion m which passes through a bore it in the primary rotor M oi the machine. This primary rotor it is rotatably sup ported .by means of tapered roller bearings !5 having 'their inner races lt mounted upon the pintle portion i?, and their outer races H set into countersunk portions i@ and !9 respectively in the ends of the primary rotor or cylinder barrel ti.

The pintle portion !2 is provided with valve openings 20 and 2 I communicating with the pintle conduits 22, 23, 24, and 25.`

The end of the pintle portion l2 is provided with an end plate 26 Secured thereto by the cap screws 21. This end plate 26 serves to retain the inner races. lE of the roller bearings !5 in place on the pintle portion !2. The cylinder barrel M is likewise provided with the annular grooves 28 and 29, encircling the pintle portion lt; on each side of the valve openings 20 and Zi. I'he primary rotor or cylinder barrel M is also provided with radially disposed cylinder bores 29a, five being shown, although a greater or lesse' number can be used, these communicating through shaft 3! having the spider portion 3 2 attached thereto. The spider portion 32 is secured to the primary rotor M by means of countersunk screws 33. The drive shaft 3! is rotatably mounted in the tapered roller bearings 34 and 35, whose inner races 36 and 31 are mounted upon the enlarged portion 38 of the drive shaft 3l, and whose common outer race 38 is mounted in a bore 48 in the projecting boss ll of the end plate 2. Leakage around the drive shaft 3! is prevented by means of the scaling ring or packing 42, which is held in place against the drive shaft 3| by means of the gland 43. The latter is held against the projecting boss ll by means of the countersunk screws u.

The outer races- I'I of the roller bearings I 5 are held in position within the countersunk portions le and |8 respectively by the projecting portion 8I of the spider 32 on the one end, and by the retaining ring. 52 bolted to the primary rotor l4 by means of countersunk screws 53 on the other end.

The annular casing portion 3 is provided with diametricaily opposite-bores 54 and 55, through which pass shifting rods 56 and 51. These rods are threadedly secured'within the bores 58 and 88 of the secondary rotor shift ring 68 in such a manner that the axis of. the latter may be shifted relative to the axis of the pintle 1. In this manner the shift ring 68 may be placed in an eccentric position relative to the pintle 1. within the secondary rotor shlft ring 60 are mounted the outer races 81 of the tapered roller bearings 62, .these being held in place by the retaining rings 63 and 84 on opposite sides thereof, through the agency of the countersunk screws 65. The inner races 66 thereof have tapered internal bores 61, which are adapted to be held on the tapered surfaces -88 of the secondary rotor halves 68 and 18 by the retaining rings 'H and 12 through the agency of countersunk set screws 13. In this manner the secondary rotor halves 68 and are free to rotate within the secondary rotor shift ring 68.

The secondary rotor halves 68 and 10 may be collectively and generally designated as the secondary rotor 14, being interconnected by the crosshead guide blocks 15. The latter are clamped between the annular-grooves 16 and 711 by means of the bolts 18. The assembly of the guide blocks and the secondary rotor halves 68 and 18 is encircled by the annular lubricant retainer 18. p

The guide blocks 15 are provided with tangentially grooved portions sofwhich are adapted to reciprocably receive the crossheads 8|-. The latter are attached to extended portions on the outer en'ds of the pistons 82 which in turn reciprocate radially within the cylinder bores 28a of 'the cylinder barrel or primary rotor H. The crossheads 8| are preferably integral with the pistons 82, thus providing thedesirable rigidity inherent in a solid piece of metal.

' The crosshead 8| of. the piston 82 (Figures 5 to 7 inclusive) has a thrust surface 83 which transmits the load to the thrust surface 84 of the guide block 18, or receives the thrust therefrom. The thrust surface 83 of the crosshead 8! is provided with transverse grooves 84a for the purpose of distributing lubricant conducted' thereto through the conduits 85 passing through the crosshead 8l. The surface of the crosshead opposite to the thrust surface 83 is provided with channeled portions 88 having side ridges 81 which also slide within the tangential grooved portions 88 of the crosshead blocks 18, whereas the channeled portions." areslightly larger than the arcuately formed projections 88 extending outward from the primary rotor ll (Figures 2, 3,

. and 6), the projection 88 being thereby freely 'much `slower rate.

son of this clearance. The arcuate projecting portions 88 termlnate in the guide walls 88 at the outer ends of the cylinder bores 28a, the guide walls 88 serving to engage the outer extended portions of the pistons 82 immediately beneath their crossheads BI.

In operation,- the secondary rotor Shift ring 68 is moved by means of Shift rods 56 and 51 until the secondary rotor 14 has its axis located eccentrically with respect to the axis of the primary rotor M and the pintle portion |2.- When power is applied to the drive shaft 3l,. assuming that the machine is being used as a pump, the pistons 82 are caused to reciprocate radially in their bores 28a by reason of this 'eccentric arrangement of the axis of the two rotors; and at the same time the piston crossheads Bl reciprocate tangentially in the grooved portions 80 of the crosshead guide blocks 15. Due to the centrifugal force set up in the operation of the machine, oil is thrown outward in a radial direction and passes through the conduits 85 of the crosshead 8l into the grooves Ma on the thrust surface 83 thereof, lubricating the latter. This provides a film of lubricant between the thrust surface 83 of the cross head 8| and the opposite thrust surface 84 of the guide block 15. At the same time, the outer extended portions of the pistons 82 immediately beneath their crossheads 8l slidingly engage the guide walls 88 of the projecting portions 88 on the primary rotor ll, thus providing an additional guiding influence upon the pistons 82, which supplements the guiding action of the cylinder bores 28.

In practice it has been found that very slight tolerances must b e maintained between the rotating parts in order that the machine shall function efliciently without excessive leakage. Accordingly, it is necessary to insure a close fit of all bearings, yet prevent metal-to-metal contact between them. To this end, the tapered roller bearings l5 and 62 have been used in preference to other forms of bearings since they provide a greater measure of adjustability. The inner races 66 of the outer roller'bearings 82 are internally tapered, as at 61, and mounfed upon the externally tapered portion 68 of the secondary rotor halves 68 and 10 in order to facilitate quick and easy assembling of the pump as well as the disassembling thereof.

In previous forms of pumps or motors employing pintles of this nature, it has been frequently found that the pintle will deflect slightly under a heavy load and cause meta-to-metal contact to take place. In the present invention, however, this deflection is efiectively reduced by means of the tapered roller hearing construction. The deformation of the hearing elements themselves is practically eliminated when the bearings are given a slight amount of pre-loading. The reason for this is that a study of the behavior of antifriction bearings having multiple rotating elements shows that the largest amount of elastic deformation occurs at a light loading; and that as the load increases the deformation increases at a Thus by slightly pre-loading the hearing, it is possible to take out most of the elastic deformation thereof.

In Figura 9 is shown a modified form of pump or motor employing ball bearings instead of roller bearings. These ball bearings 88 and 8| may be arranged singly or'in pairs, the latter construction being shown. In use these ball bearings 88 are given a slight amount of preloading in order to remove the elastic deformation thereof. as exdrive shaft portion e between the outer races 92 and 93 and the inner races 94 and 95.

The support of the entire outer end of the cylinder rotor |4` and the pintle portion l2 by the 38 in the roller hearing 34 and 35 gives a', Construction which contributes to extremely close fits of the rctating parts, yet prevents e'xcessive deformation thei-cof. In this 'manner a very solid construction is obtained and metal-to-metal contact substantially done away with.

It will be understood that the machine of this invention can be employed either as a. pump or as a motor. In using it as a pump, power is applied to the drive shaft 3! and oil supplied through the valve openings 20 and 2+-in the pintle 1. In using the machine as 'a motor, however, fluid under pressure is supplied through one of the valveopenings 20 or 2I, whereupon' the eccentric arrangementof the primary and secondary rotors causes the pistons 82 to reciprocate, thus applying power to the 'secondary rotor or cylinder barrel M; this power is then communicated to the drive shaft 3! through the spider 32 forming a connection therebetween.

It will be understood that in the present invention I have provided preloaded ball bearings which are slightly larger in diameter than the space between their races, the balls being forced into this space in such a'manner that the clearance between. the races. and the balls is substantially zero. In this manner I maintain a fluid-tight connection between the fluid-distributing valve or pintle and the cylinder barrel at high pressures. and yet prevent metal-to-metalcontact therebetween.

It will be understood that I desire to comprehend within my invention such modiflcations as may be necessary to adapt it to varying'bonditions and uses. x

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is: i

`1. A fluid pressure pump or motor including a cylinder body, a fluid distributing valve, said cylinder body and said fluid distributing valve being mounted for rotation relatively to 'one another,

cylinders in said cylinder body arranged to comthe ball bearings andmunicate with said fluid distributing valve, pistons arranged to' reciprocate in said cylinder-s;

means for reciprocating said pistons, and preloaded ball bearings mounted between said cylinder body and said distributing valve, the diametral clearances of said preloaded ball bearings being reduced to substantially zero, the clearance between said cylinder body and said fluid distributing valve being greater than the total diametral clearance o said preloaded ball bearings.

2. A fluid pressure pump or motor including a cylinder body, a fluid distributing valve, said cylinder body and said fluid distributing valve being mounted for rotation relatively to one another cylinders in said cylinder body arranged to communicate with said fluid* distributing valve, pistons arranged to reciprocate in said cylinders, means for reciprocating said pistons, and preloaded ball bearings mounted betweensaid cylinder body and'said 'distributing valve, the diametral clearances of said preloaded ball bearings being reduced to substantially zero, the clearance between said cylinder body and said fluid distributing valve being greater than the total ings, said preloaded ball bearings being arranged in paired assemblies at opposite ends of said cylinder body.

3. A fluid -pressure cylinder body, inder body and saidfluid distributing valve being mounted for rotation relatively to one another, cylinders in said cylinder body arranged .to communicate with said fluid distributing valve, pistons arranged to re iprocate in said cylinders, means for reciprocating said pistons, and preloaded ball bearings mounted between said cylinder body andsaid distributing valve, the diametral clearances of said preloaded ball bearings being reduced to substantially fzero, the clearance between said cylinder body and said fluid distributing valve being greater than 'thetotal diametral clearance of said ings, said preloaded ball bearings being arranged in paired assembues at. opposite ends of said cylinder body, each of said hearing assemblies including a plurality of rows of preloaded ball bearpump or motor including a.

a fluid distributing valve, said cylpreloaded ball bea'r- 

